The process of blood coagulation (thrombogenesis) results in blood dotting and involves a coagulation cascade of many factors most of which are enzymes which cleave downstream proteins in the coagulation process. The ability to maintain proper clotting balance is critical. Disorders that effect coagulation of blood can lead to uncontrolled bleeding (hemorrhage) or uncontrolled clotting (thrombosis) that can prevent blood flow to critical organs such as, for example, the heart or the brain.
Many tests are available to evaluate the function of the clotting system in mammals. Currently, one of the most informative methods of testing the efficiency of the dotting system is thromboelastography (“TEG”). For a recent review see Trapani, L., “Thromboelastography: Current Applications, Future Directions,” Open Journal of Anesthesiology, January 2013. TEG, in its original format, uses a sample of blood that is placed in a cuvette and rotated about a thin wire (wetted member) that measures clot formation, clot strength and other parameters. In an alternate form, known as rotational thromboelastometry (ROTEM), the sample remains stationary, but the shaft includes a sensor pin to measure various parameters as the shaft rotates within the well in which the blood sample is disposed. Conventional TEG devices are large and expensive, which limits their availability. The basic mechanism and design of conventional TEG devices is not conducive to miniaturization.
The presently described methods and devices provide a novel mechanism and device to measure blood coagulation parameters which represents a microelectromechanical system (MEMS). The miniaturization possible with this design allows the device to be constructed as a single-use sealed and disposable with or without all electronics built into the package. This offers many advantages, including but not limited to, a reduction in the volume of the blood sample required, the expense of the test and allows bedside (point of care) application and enhances both safety and convenience.